Contact locating method



Aug.2o, 1946. 1H. AHL l2,406,25517 A CONTACT LOQATING METHOD Filed Jan. 30, 1942 IN VEN TOR.

./arrg Zkzhl BY W MW Patented Aug. 20, 1946 CONTACT LOCATING METHOD Harry Dahl, Indianapolis, Ind., assigner to P. R.

Mallory & Co., Inc., Indianapolis, Ind., a corporation of Delaware Application January 30, 1942, Serial No. 428,830

(Cl. 22B-155.55)

3 Claims. 1

This invention relates lto electric contact methods for locating and securing the same to backlngs.

An object of the invention is to improve the methods for positioning contacts on backings.

Other objects o-f the invention will be apparent from the following description and accompanying drawing taken in connection with the appended claims.

The invention comprises the features of construction, combination of elements, arrangement of parts, and methods of manufacture and operation referred to above or which will be brought out and exemplified in the disclosure hereinafter set forth, including the illustrations in the drawing.

In the drawing:

Figure 1 is a vertical section through a contact backing and a locating tool for preparing said backing to receive a contact;

Figure 2 is an underneath view of said tool;

Figures 3 and 4 illustrate the method of preparing the backing;

Figures 5 and 6 show the completed backing; and 101Figure 7 shows the completed contact assem- Up to the present time, considerable difliculties have been encountered in accurately locating contacts on blanks for such operations as brazing, resistance welding, electrobrazing, etc. Wherever it is possible, welding tables have been provided so that the contacts during the brazing operation would center properly. Y In blanks of heavier thickness it is difficult to yprovide welding tables and it has become necessary to use either special boats in furnace bracing or expensive welding fixtures for electrobrazing and resistance welding.

The present invention overcomes these difficulties and provides accurate means to produce ears on the contact blanks for accurately locating the contacts on a at surface,

While a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of procedure and the construction of parts without departing from the spirit of the invention. In the following description and in the claims, parts will be identied by specic names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to the drawing the locating tool I0 is provided with a shank I I for clamping by the ZIJ tool holder of a suitable press, such as a kick press, punch press or any power press, having a flat bed I2. Tool I0 is provided with a central hold-down punch I3 which is urged by coil spring I4 toward the bed of the press and is sidable in central guide bores I5 and I6.

A collar il encircles the lower portion of holddown punch I3 and is slidable thereon. It is retained in position by the heads of three spaced bolts I8 upon which bolts it is slidable. Bolts I8 are secured in the body of tool I0 and surrounded by coil springs I9 which urge collar I'I downward against the head-s of bolts I8. Collar II carries three spaced staking punches 20 extending diagonally downward and inward from the outer edge of the upper beveled surface of the collar. These staking punches are slidable in their guideways but are prevented from rotating by set screws 2| and are normally retracted upwardly by encircling coil springs 22 so that their heads pro-ject above the beveled upper surface of collar I'I. The main body of tool I0 has an inwardly beveled flange 23 which engages the heads of staking punches 20. The tips of punches 20 may be squared or of other suitable design.

In operation the contact backing blank 2A, which may, for example, be a flat elongated c`ontact arm, is laid on the bed I2 of the press and located in position by a suitable Xture. The tool I0 is then brought down against it by the operation of the press. The blank is rst engaged by hold-down punch I3 which holds it firmly in position under spring pressure. As Ithe tool continues to descend, collar I'I comes into contact with the blank and is held against it by spring pressure. As the tool descends further flange 23 on the tool body engages the heads of staking punches 20 and forces them downward and inward causing them to sink into the surface of the blank 24 and press up ears 25 at three spaced points around the periphery of hold down punch I3, as shown in Figure 3.

It may be that this operation will force punch I3 up a little due to the raising of metal, as shown in Figure 3. If this takes place, the central area can be coined and flattened by bringing the tool down until the end wall'of guide bore I5 engages the shoulder of the hold-down punch, thereby forcing it firmly down on the blank to effect a coining operation, as indicated in Figure 4. In some cases the coining may not be required.

The completed blank 24, shown in Figures 5 and 6, has a plane central, area surrounded by three spaced locating ears 25, A disc contact 25 of such size as to t the space provided can therel by be readily positioned for brazing =by a brazing layer 27, as shown, or by resistance welding or other methods.

While the present invention, as to its objects and advantages, has beendescribed herein as carried out in specific embodiments thereof, it is not desired to be limited thereby but it is intended to cover the invention broadly within the spirit. and scope of the appended claims.

What is claimed is:

' 1. The method of preparing a contact mount ing Vblank Which comprises clamping a selected plane surface area of said blank With the plane l H end of a holding punch in'simulation of a contact and then forging up a series of locating ears from the material of said blank against the edge 'of said hold-down punch While substantially maintaining said clamped plane surface area of said blank, and then coining said selected area 1V of vsaid blank with said Yholding punch to atten out any Virregularities produced in said selected area by the foregoing operation. .y 2. The methodY of securing a Contact to a substantially plane mounting blank free from 're-t cesses and similar locating elements which com- 3. The method of preparing a contact mounting blank which comprises providing a substantially plane mounting blank freerom recesses and similar locating elements, applying the plane end of a cylindrical holding punch of the size of the contactV desired t0 be mounted' against a selected plane surface area of the face of said blank, engaging a portion of the surface of said blank annularly adjacent and encompassing said plane surface area with a second and ring-like holding member, and applying force through openings in said second holding member to spaced points of the blank to produce upward flow of thematerial in said region against the edge and sides of.

said cylindrical holding punch thereby to dene a contact holding socket.- Y

HARRY DAI-IL. 

